Perceived Dissmilarity and Relational Self-Expansion in Close Midlife Friendships

Previous research finds that perceived similarity in friendships is predictive of attraction and friendship satisfaction. People are often interested in forming and maintaining friendships with others who seem more similar to themselves, as it can predict greater compatibility. In contrast, according to self-expansion theory, some dissimilarity (i.e., personality, interests, or attitudes) may provide advantages to relationships by encouraging self-expansion. Relational self-expansion—the growth of a person’s self- concept through newer and broadened experiences and perspectives facilitated by another—is strongly predictive of relationship satisfaction. However, most research on the topic is limited to romantic contexts. The current study explored two competing hypotheses in the context of friendships, namely whether perceived dissimilarity predicts a) higher self-expansion and friendship satisfaction or b) lower self-expansion and friendship satisfaction. I also examined self-concept clarity—how clearly defined and stable one’s self-beliefs are—as a moderator of self-expansion, with higher scores predicted to be associated with higher self-expansion. To explore these hypotheses, midlife adults (N = 241) completed questionnaires assessing perceived general similarity, relational self-expansion, friendship satisfaction, and self-concept clarity related to their closest friendship. I conducted a moderated-mediation model to assess whether the link between perceived dissimilarity and friendship satisfaction is due in part to self-expansion, especially for people who score relatively low or high on self-concept clarity. Self-concept clarity did not moderate this association. Self-expansion was found to mediate the negative association between perceived dissimilarity and friendship satisfaction. Results suggest that perceived dissimilarity may be detrimental to friendship quality by limiting self- expansion opportunities.